Integrating PCS 7 APL Technological Blocks and Faceplates into S7-300 and WinCC Projects

Deploying standard SIMATIC PCS 7 Advanced Process Library (APL) technological blocks—such as MotL (FB1850)—into standard STEP 7 and WinCC projects with S7-300 CPUs fails because APL blocks rely on system function block SFB35 (ALARM_8P) and proprietary C-script runtime DLLs that do not exist in standard S7-300 and WinCC installations. Copying block icons from @PCS7typicalAPL.pdl without these underlying libraries results in broken faceplate calls and script errors. To implement APL look-and-feel on S7-300 controllers, use the dedicated SIMATIC PCS 7 Industry Library (IL), which provides tailored function blocks and WinCC Comfort/Professional faceplates.

Architectural Incompatibilities Between PCS 7 APL and Standard S7-300/WinCC

Engineers frequently seek to utilize the sophisticated visualization, operating modes, and interlocking features of the PCS 7 Advanced Process Library (APL) in smaller automation projects running on SIMATIC S7-300 controllers (e.g., CPU 315-2 PN/DP 6ES7315-2EH14-0AB0) and standalone WinCC SCADA systems.

However, attempting to copy APL function blocks (such as MotL FB1850 or VlvL FB1899) and paste their block icons from @PCS7typicalAPL.pdl into a standard WinCC project encounters severe architectural barriers:
* Controller Firmware Level: Standard S7-300 operating systems lack the microcode firmware routines required for multi-instance alarm generation (SFB35 ALARM_8P).
* WinCC Graphics Engine Level: APL block icons and faceplates do not rely on standard dynamic dialogs; they invoke proprietary ANSI-C functions (e.g., APL_OpenFaceplate, APL_ConfigureFaceplate, APL_UpdatePermission) packaged inside internal PCS 7 OS DLLs (s7apl*.dll) that are absent in standalone WinCC installs.

Why ALARM_8P and APL Faceplate Scripts Fail on S7-300

The technical reasons standard APL blocks cannot execute on S7-300 controllers are detailed below:

Subsystem / FeaturePCS 7 APL Standard (S7-400)Standard S7-300 ControllerFailure Mode on S7-300Alarm SignalingSFB35 (ALARM_8P) native firmware supportNot supported on standard S7-300 CPUsController CPU STOP: Unresolved SFB call during download.Data Memory FootprintLarge multi-instance DBs (> 10 KB per block)Limited work and load memoryMemory bottleneck; limited number of instances can be loaded.Faceplate Runtime DLLss7apl*.dll installed by PCS 7 OS setupAbsent in standalone WinCC SCADARuntime C-script failure: APL_OpenFaceplate undefined in apdiag.exe.Picture Naming Scheme@PG_<BlockType>_STANDARD.pdl structureRequires manual configurationFaceplate opens as blank picture window or fails to resolve server prefix.

Table 1: Compatibility barriers between standard PCS 7 APL blocks and S7-300 systems.

The Certified Solution: SIMATIC PCS 7 Industry Library (IL)

To bridge this gap, Siemens developed the SIMATIC PCS 7 Industry Library (IL) (6ES7658-2HX...). The Industry Library provides:
* Dual Library Architecture: Includes an AS section for S7-400 and a dedicated AS section for S7-300 controllers.
* S7-300 Optimized Blocks: Function blocks (such as IL_MotL, IL_VlvL, IL_MonAnL) programmed to deliver identical APL look-and-feel, operating modes, and interlocks while utilizing standard S7-300 communication blocks (such as SFC17/SFC18 or bit-based alarms) instead of ALARM_8P.
* Standardized Panel and SCADA Faceplates: Pre-built faceplates designed for WinCC Comfort / Advanced TIA Portal panels as well as classic WinCC SCADA.

Step-by-Step Procedure to Integrate Industry Library with S7-300 and WinCC

To implement standardized APL-style motor and valve control on an S7-300:

Install Industry Library:
* Install the SIMATIC PCS 7 Industry Library package on the Engineering Station.
Import S7-300 Blocks into STEP 7:
* Open the Industry Library catalog under Libraries > Industry Library S7-300.
* Copy the required blocks (e.g., IL_MotL FB1250) into the S7-300 block folder.
Configure Technological Logic in CFC / LAD:
* Instantiate IL_MotL and assign an instance DB.
* Connect digital inputs, motor feedback, and interlocking signals (Permit, Protect).
Compile OS and Generate WinCC Tags:
* In SIMATIC Manager, execute Compile OS: the compiler transfers the technological tag structure into WinCC Tag Management.
Insert Industry Library Block Icons:
* In WinCC Graphics Designer, open the Industry Library typicals picture (@IL_Typicals.pdl).
* Copy the block icon into your plant overview picture.
* Use the dynamic wizard or connect the Tag property to the S7-300 motor instance DB.
* In runtime, clicking the icon opens the certified IL_MotL faceplate without missing DLL errors.

Verification

To confirm proper operation of Industry Library blocks on S7-300:

Download the S7-300 program: verify that the CPU transitions to RUN mode without SFB execution errors in the diagnostic buffer.
Launch WinCC Runtime on the operator station.
Click the motor block icon: verify that the faceplate opens displaying the standard APL layout (Mode, Status, Command buttons, Interlocks).
Run apdiag.exe from C:\Program Files (x86)\Siemens\WinCC\utools\: verify zero missing function or C-script compilation errors.
Command the motor to Start/Stop from the faceplate: verify that the physical S7-300 digital output energizes accordingly.

Limitations and Operational Precautions

Never attempt to force standard PCS 7 APL v8/v9 blocks into S7-300 controllers; doing so can cause CPU crashes and violates Siemens software architecture rules.
Operating the Industry Library requires dedicated engineering and runtime licenses (6ES7658-2HX...). Always validate licensing packages and MLFBs with an authorized Siemens distributor.
S7-300 controllers feature significantly smaller communication connection resources than S7-400; monitor configured connection limits when integrating multiple WinCC clients.

Engineer FAQ

Can an S7-319 CPU run standard PCS 7 APL blocks?

While CPU 319-3 PN/DP possesses higher processing power, standard APL blocks still fail because standard S7-300 operating systems do not support the full SFB35 ALARM_8P message configuration required by PCS 7 OS compilation.

Where are APL faceplate C-scripts located?

Standard APL faceplate scripts are compiled C-actions located in the project's Library directory and system DLLs (aplib) installed exclusively with the PCS 7 OS package.

Can Industry Library faceplates be used on Siemens Comfort Panels?

Yes. The Industry Library includes pre-engineered TIA Portal faceplates for SIMATIC Comfort Panels (6AV2124-0MC01-0AX0), allowing identical operator look-and-feel across local touchpanels and central WinCC SCADA.